dev-arm: Allow 32-bit access to GITS_TYPER

Change-Id: I9d19174b38ba70f82050102f955ccc162965d1fb
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20618
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/dev/arm/gic_v3_its.cc b/src/dev/arm/gic_v3_its.cc
index 4108cc7..ca363f4 100644
--- a/src/dev/arm/gic_v3_its.cc
+++ b/src/dev/arm/gic_v3_its.cc
@@ -836,6 +836,10 @@
         value = gitsTyper;
         break;
 
+      case GITS_TYPER + 4:
+        value = gitsTyper.high;
+        break;
+
       case GITS_CBASER:
         value = gitsCbaser;
         break;
diff --git a/src/dev/arm/gic_v3_its.hh b/src/dev/arm/gic_v3_its.hh
index 40d95c8..b9c1d85 100644
--- a/src/dev/arm/gic_v3_its.hh
+++ b/src/dev/arm/gic_v3_its.hh
@@ -196,6 +196,8 @@
     EndBitUnion(BASER)
 
     BitUnion64(TYPER)
+        Bitfield<63, 32> high;
+        Bitfield<31, 0> low;
         Bitfield<37> vmovp;
         Bitfield<36> cil;
         Bitfield<35, 32> cidBits;